What’s the real secret of children not becoming fat? Recent government pronouncements on combating the child obesity “epidemic” have concentrated on healthy eating; Ruth Kelly, the Education Secretary, announced last week an end to fizzy drinks, chocolate and crisps in school vending machines. But there are fears that the other side of the fat equation — how to get children to exercise — is being overlooked amid all the agonising about junk food.

A recent study in the Journal of the American Medical Association indicated that if people who were overweight exercised enough, then their life expectancy was the same as people of average weight and better than people who were underweight. If patterns for life are set in childhood, maybe it’s the exercise that we should be getting right first.

As the National Obesity Forum prepares to meet in London next week to debate preventing weight gain in children, new studies suggest that it’s no good just telling kids to exercise more. It doesn’t work. It’s all to do with motivation, family involvement and lack of embarrassment. The New Leaf Project — a collaboration between the University of Chichester and St Richard’s Hospital, West Sussex — is about to publish the findings of a five-year study into its work with 750 overweight children, aged 7 to 16, from local schools. It has found that dietary treatment alone is largely ineffective in treating childhood obesity. What has worked is fitness clubs, where the fear factor has been removed from exercise, and schemes in which families are involved, and in which children have been motivated not by measuring how fat they are, but showing them how much muscle they are gaining. Children would rather be superheroes than problem kids.

“We’ve been working with children who have found sport a turn-off,” says Professor David Candy, a paediatric gastroenterologist at St Richard’s who runs the project. “Because of their bodies, they don’t like getting changed in front of others and they’re very conscious that they never get picked for teams.”

It isn’t just overweight children who face such psychological barriers to activity. A recent report from Bath University found that half of all girls under 16 felt embarrassed about exercising in front of people. A third said that they didn’t exercise because they were no good at sport.

The physical education experts at Chichester University who run the New Leaf fitness club have devised games, such as football with two balls, where exercise becomes funny and fun. “It helps a lot when you take them out of the context of school, which can be quite competitive,” says Julia Potter, a senior PE lecturer at Chichester. “Inviting in families and friends to participate is hugely important, too. We try to organise walks and trips which can motivate everyone to change family routines,” she says.

“One of the underpinning things has been to measure fitness throughout, and how much of the children’s excess weight is fatty tissue and how much muscle and bone,” says Candy. Throughout the project, he and other staff have been using body composition monitoring (see box), rather than body mass index or waist circumference readings to assess how well the children are doing. “It has shown that some children who have been classified as obese aren’t; they’re heavy because of muscle, not fat, and that’s far less dangerous. It has proved quite an incentive for the children, too. We are measuring their muscles rather than asking them how fat they are.”

Since the programme began, one third of the children who have participated have achieved long-lasting fat (not crude weight) loss, a high success rate compared with other projects.

It’s not an isolated breakthrough. Newly released research, after a family cycling event in Manchester this July organised by GSK Nutritional Healthcare, showed that if you make exercise family-orientated, cool and non- competitive, children keep on doing it. A survey by Research International found that four weeks after the event, 43 per cent of the children attending were still cycling.

It all makes perfect sense, according to Professor Ken Fox, from the Centre for Sport, Exercise and Health at Bristol University. “Children up until the age of 10 aren’t capable of thinking in abstract terms about exercise, health and fitness,” he says. “They’ll do what feels good now or what pleases other people, which is why the family can be such an influence at this age.”

It worries Fox that government interest in child exercise seems almost exclusively concentrated on competitive sports, not the sort of non-threatening activity exemplified by New Leaf, Go-Ride-In, or, indeed, the surprisingly popular weightlifting classes he ran for girls when he was a schoolteacher — activities that are fun but where you can measure success in terms of changes in your own body. “Yes, we do need more sport,” he says, “but the really important question to address is what you do to make sure it appeals to a wide range of children.”

Ways to measure weight

Body mass index BMI — the current standard — calculates whether you are of average weight for your height. It is a rough indication that takes no account of build or muscularity.

Waist circumference This is a measurement advocated by the National Obesity Forum as the best way of identifying people at risk of type 2 diabetes. Visceral fat, which accumulates in the abdomen, is said to be the most dangerous.

Body composition monitoring These readings are taken electronically through foot and hand electrodes. They can tell the body’s total fat, muscle and water content. This was favoured by the New Leaf researchers, whose work was supported by the monitor manufacturers, Tanita.

Explore Health News

• Swine flu

Times Recommends

• Charles blazes trail as sun king
• Thalidomiders win payout 50 years on
• Libel gag on talk of 'medical hurricane'